A group claiming to be affiliated with hacktivist collective Anonymous has threatened to release the name of the police officer who shot unarmed teen Michael Brown in the town of Ferguson, Missouri.

Operation Ferguson says it is a group of hackers linked to Anonymous. It was set up a day after the 18-year-old black man was shot six times, reportedly by a police officer, despite eyewitness claims that he attempted to surrender.

In a press release posted to Pastebin on Sunday, “Anonymous Operation Ferguson” said that the global collective was outraged at the events in Ferguson and demanded new legislation setting strict guidelines for police conduct in the US. The group also threatened to take down the websites of authorities in the town if they “abuse, harass or harm in any way protestors in Ferguson”.

The hackers appeared to make good on the threat on Tuesday, taking down the website of City Hall as well as phone lines and email systems in a flood of traffic that “just kept coming”, the St Louis Post-Dispatchreported.

Operation Ferguson took credit for the outages on its newly created Twitter account.

The group then tweeted that it had the name of the officer who shot Brown, which was being withheld by the police after threats on social media. So far, the hackers have not released the name, saying that they want to be certain of the officer’s identity first.

Ok look folks; we are NOT going to release the name of the shooter until we are absolutely certain we are correct. | #Anonymous#OpFerguson

Operation Ferguson’s threats come after another Anonymous group tweeted that they would publish information on the daughter of St Louis County’s police chief Jon Belmar if he refused to release the officer’s name. @TheAnonMessage eventually backed down on its threats, saying that they were “damaging to the overall message of justice for Mike Brown”.

We recognize that Jon Belmar has had enough damage done to him. We will save the rest of our energy for the true perpetrator. #Ferguson

Ferguson has been the scene of protests, rioting and looting since Brown was shot and killed while reportedly trying to surrender to police. According to an interview with MSNBC, Dorian Johnson was walking down the middle of the road with Brown when a police officer driving down the road told them to get onto the sidewalk. After a struggle at the car window Brown was shot, Johnson told the news network.

Johnson and Brown both started to run away and Brown was shot again in the back. Johnson claims Brown then turned around with his hands up, telling police he didn’t have a gun and to stop shooting, after which he was reportedly shot again multiple times.

Other eyewitness accounts agree with Johnson’s, but police claim that Brown was killed after a struggle over the officer’s gun. ®